Novel 2D and 3D indium metal-organic frameworks:: Topology and catalytic properties

Four novel metal-organic frameworks (MOFs) [In(BDC)(1.5)(bipy)] (1), [In-2(OH)(2)(BDC)(2)(phen)(2)] (2) [In(BTC)(H2O)(bipy)] (3), and [In(BTC)(H2O)(phen)] (4) (BDC = 1,4-benzendicarboxylic acid, BTC = 1,3,5-benzenetricarboxylic acid, bipy = 2,2'-bipyridyl, phen = o-phenantroline) were synthesized and their structures were determined by X-ray single-crystal diffraction. Structurally speaking we can conclude that while the metal/connector/chelate rate is 1: 1: 1, the introduction of a chelate ligand, such as bipy or phen, blocks the possibility of connections in one direction, inducting the formation of 2D structures. In the case of compound 1, the extra one-half of BDC ligand per indium favors the eight coordination of the metal and drives the formation of a catenated 3D structure. Topological studies on the four compounds show one inclined catenation of hexagonal layers for I and three interdigitated layered structures with 2D topologies of type (4(4)), (6(3)) and (4.8(2)) for 2, 3, and 4 compounds, respectively. Three of the new In compounds are active and selective acid catalyst in acetalization of aldehydes.